configs: am57xx_evm: Enable Android commands

Enable Android commands that will be needed for Android 10 boot flow
implementation, for all AM57x variants. Commands enabled:

  1. 'abootimg':
     - CONFIG_CMD_ABOOTIMG=y
  2. 'ab_select':
     - CONFIG_ANDROID_AB=y
     - CONFIG_CMD_AB_SELECT=y
  3. 'avb':
     - CONFIG_LIBAVB=y
     - CONFIG_AVB_VERIFY=y
     - CONFIG_CMD_AVB=y

While at it, resync defconfig files with "make savedefconfig".

Signed-off-by: Sam Protsenko <joe.skb7@gmail.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>